Meningococcal ACWYX Conjugate Vaccine in 2-to-29-Year-Olds in Mali and Gambia

This phase 3, double-blind, randomized, noninferiority trial compared a new pentavalent meningococcal conjugate vaccine (NmCV-5) targeting serogroups A, C, W, Y, and X, with the licensed quadrivalent MenACWY-D vaccine. Conducted in Mali and Gambia among 1800 healthy participants aged 2–29 years, the study evaluated immunogenicity at 28 days post-vaccination. Seroresponse rates with NmCV-5 ranged from 70.5% (serogroup A) to 98.5% (serogroup W); for serogroup X—absent in comparator vaccines, response was 97.2%. GMT ratios for shared serogroups favored NmCV-5 (e.g. 2.8 for serogroup C). Noninferiority criteria were met for all serogroups including X. Safety profiles were similar between groups with no vaccine-related serious adverse events. NmCV-5 demonstrates strong immunogenicity, safety, and potential to address epidemic meningitis across the African meningitis belt, including coverage of serogroup X previously lacking in licensed vaccines.

This phase 3, double-blind, randomized, noninferiority trial compared a new pentavalent meningococcal conjugate vaccine (NmCV-5) targeting serogroups A, C, W, Y, and X, with the licensed quadrivalent MenACWY-D vaccine. Conducted in Mali and Gambia among 1800 healthy participants aged 2–29 years, the study evaluated immunogenicity at 28 days post-vaccination. Seroresponse rates with NmCV-5 ranged from 70.5% (serogroup A) to 98.5% (serogroup W); for serogroup X—absent in comparator vaccines, response was 97.2%. GMT ratios for shared serogroups favored NmCV-5 (e.g. 2.8 for serogroup C). Noninferiority criteria were met for all serogroups including X. Safety profiles were similar between groups with no vaccine-related serious adverse events. NmCV-5 demonstrates strong immunogenicity, safety, and potential to address epidemic meningitis across the African meningitis belt, including coverage of serogroup X previously lacking in licensed vaccines.